EQMResearch group
Changelog

What's new

Recent changes to the simulator, plus the current known limitations.

Current limitations
  • Simulation cost scales with the number of optical layers (magnetic domains), not the raw layer count. A spin pattern that expands into more than 2,000 optical layers (domain boundaries) is rejected with a message — use larger AFM/FM domains or fewer layers.
  • Large stacks are smooth only when they form a few domains: the layer editor is virtualized and the stack heatmap is downsampled above ~2,000 rows to stay responsive.
  • Saved configurations live in this browser only (local storage), are capped at 30 entries, and are lost if you clear site data.
  • Extremely thick or opaque stacks can reach the numerical-precision limits of the transfer-matrix method.

June 2026

  • ImprovementTop gold mirror off by default

    The Au top mirror now starts disabled, so the bare DBR + CrSBr response is shown first. Re-enable it any time from the stack parameters.

  • ImprovementReflectance & electric field in one container

    The two plots share a single tabbed card sized so neither requires scrolling.

  • FixGold plate starts at z = 0

    The electric-field depth axis is shifted so the top of the gold plate sits at z = 0 instead of 50 nm.

  • FeatureUp to 100,000 layers

    The layer cap was raised to 100,000. The editor is virtualized and the stack heatmap downsamples so rendering stays responsive.

  • FeatureExport menu on every graph

    A download menu pinned to each card's top-right corner exports the stack viewer, reflectance, and electric-field plots as PDF, PNG, or CSV (raw values).

  • FixZoom is preserved on parameter changes

    Re-running the simulation no longer resets a zoomed-in graph back to full scale.

  • FeatureSaved configurations

    Save the full stack and parameters to local storage, then load or delete past configurations from the sidebar.

  • FixClear message for over-complex stacks

    Patterns with too many magnetic domains now return an instant, explanatory message instead of a slow request that failed with a 500 error.

May 2026

  • FeaturePer-layer spin editor

    Build a CrSBr stack by setting each monolayer's spin up or down, with bulk tools to reset to AFM, flip a range, set all up/down, or randomize.

  • FeatureMagnetic phase classification

    Neighbouring spins are classified into AFM, Mixed, and FM domains and colour-coded across the editor and stack viewer.

  • FeatureTransfer-matrix reflectance

    A FastAPI backend computes the reflectance spectrum R(E) of the full Au / CrSBr / DBR stack using the transfer-matrix method.

  • FeatureElectric-field profile

    Visualise the |E(z)|² depth profile at a selectable photon energy, picked directly from the reflectance curve.

  • FeatureStack viewer

    An interactive cross-section shows the gold mirror, CrSBr layers coloured by phase, and the DBR pairs to scale.

  • FeatureAdjustable stack parameters

    Tune the gold thickness, DBR pair count and centre wavelength, energy range and resolution, and the field-probe energy.

  • FeatureLearn section

    Built-in explainer pages and inline term tooltips cover the physics behind the simulator, from spins and photons to the transfer-matrix method.